1. Field of the Invention
The present invention relates to a laser induced thermal imaging (LITI) apparatus and a laser induced thermal imaging method, and an organic light emitting display device using the same, and more particularly, to a laser induced thermal imaging apparatus and a laser induced thermal imaging method, and an organic light emitting display device for performing a process of laminating a donor film and an accepter substrate using a magnetic force.
2. Discussion of Related Art
An organic light emitting device includes a light emitting layer formed between first and second electrodes and emits light when a voltage is applied between the electrodes. Hereinafter, prior art and embodiments of the present invention will be described in reference to the laser induced thermal imaging apparatus used for fabricating an organic light emitting device, but the present invention is not limed thereto.
A laser induced thermal imaging method radiates a laser on a donor substrate including a base substrate, a light-to-heat conversion layer and a transfer layer (or imaging layer), and converts the laser that passes through the base substrate into heat in the light-to-heat conversion layer, such that the light-to-heat conversion layer is deformed and expanded. This way, the transfer layer is adhered to the acceptor substrate, such that the transfer layer can be transferred to the acceptor substrate.
When performing the laser induced thermal imaging method, the inside of a chamber in which the transfer is performed should be in a vacuum state. However, in the prior art, there is a problem that the imaging layer is not transferred well because a space or impurities are created between the donor substrate and the accepter substrate when a laser-to-heat conversion is performed in the vacuum state. Therefore, in the laser induced thermal imaging method, the method of laminating the donor and accepter substrates is important, and to address the problems that arise during lamination, various methods have been investigated.
FIG. 1 is a partial cross-sectional view of a laser induced thermal imaging apparatus according to prior art for resolving the above-mentioned problems. According to FIG. 1, a laser induced thermal imaging apparatus 10 includes a substrate stage 12 placed in a chamber 11 and a laser oscillator 13 placed at an upper portion of the chamber 11. The substrate stage 12 is a stage for supporting an accepter substrate 14 and a donor film 15 introduced into the chamber 11.
For laminating the accepter substrate 14 and the donor film 15 without space or impurities between them, when the accepter substrate 14 and the donor film 15 are adhered with each other in the chamber 11 in which the laser-to-heat conversion is performed, the chamber 11 is not maintained in vacuum but particles or impurities in the chamber 11 are absorbed by a vacuum pump P.
However, in this prior art, it is difficult to absolutely prevent creating impurities 1 and the space between the accepter substrate 14 and the donor film 15 and maintain a vacuum state in the chamber 11. It is well known in the art that reliability and durability of products are adversely affected when the space and/or the impurities are present between the acceptor substrate and the donor film.